Phylum Porifera Grant, 1836 - sponges Class Demospongea Sollas, 1875 see Class Demospongiae Sollas, 1885 Subclass †Lithistida Schmidt, 1870 Order Tetralithistida Lagneau-Hérenger, 1962 Suborder Tetracladina Zittel, 1878 Family Theonellidae Lendenfeld, 1903 Subfamily †Acrochordoniinae Schrammen, 1910 Genus †Ragadinia Zittel, 1878